The present invention relates to a load adjustment device having a control element for acting on a setting member which determines the output of an internal combustion engine. The control element cooperates with a driver which is coupled to an accelerator pedal and, in addition, can be moved by means of an electric setting drive. There is a desired-value detection element associated with the driver, and an actual-value detection element cooperating with the driver and acting on the electric setting drive. The electric setting drive is controllable by an electronic control device as a function of the values detected.
A load adjustment device of this type is known from Federal Republic of Germany patent document 38 15 734 A1. In it the driver and the control element are coupled by means of a coupling spring and the control element is urged in the direction of a stop on the driver. The position of the driver is indicated by the desired-value detection element, and the position of the control element by the actual-value detection element. The values detected by the two elements are forwarded to an electronic control device which controls the control element cooperating with the setting member via an electric setting drive in accordance with a control characteristic predetermined between the two elements. The coupling spring in this connection makes certain that, upon divergent movements of driver and control elements, a failure of the electronic control device always leads to a change in the setting of the load to a value of the output which corresponds to the value of the accelerator pedal.
Said load adjustment device has, in principle, proven itself in practice. Nevertheless, there are conceivable in connection with it operating conditions in which, with the electric setting drive activated, the control element must also move the driver, and this even against the restoring forces acting on the driver. This requires a stronger development of the setting drive and of an electromagnetic switch clutch arranged, for instance, behind said drive. Furthermore, a reaction-free operation of the control element and thus of the setting element is not assured in all operating conditions of the load adjusting device.